Production of ammonium compounds



Aug. 22, 1933. F. JOST ET AL 3 PRODUCTION OF AMMONIUM COMPOUNDS Filed Feb. 6, 1930 2 Sheets-Sheet, 1

a m m om'a a 6' acid N prelim/nary A nemra/izer ammonia main neutral/hr I71 re r7 or's fivbarv'c/r Jan and Gain/her Horrumy 5y Aug. 22,1933. JOST AL 1,923,212

PRODUCTIOfi OF AMMONIUM COMPOUNDS I Filed Feb. 6, 1930 2 Sheets-Sheet 2 Fl B l.

ammo/11.21

ammo/1 fa min malrah'z'er Patented Au 22,1933

' monUo'rroN or momuuoomrotmnsl Switzerland L ents Explcitation Cy. Alpinifl Ltd, Bosch Appli ation February 6, 1930, Serial unllzsnze," I t 4 andinGermany Februa y 1 ,1929

14 Claims.

- 'M invention raters to the production of chem- -ioaleompounds produced by, a. basic substance with an acid for partial or. total neutral- Auction. It has particular reference to the pro- 15 duction of ammonium salts, such as ammonium sulfate or ammonium nitrate from ammonia and sulfuric acid or nitric acid. One of its objects is tc'improve the saturation process in order-to save time and energy and to increase the yield of the final products to be obtained. f

Hitherto ammonium salts, for instance am+ memum sulfate, have been produced by conduct- ,ing ammonia gas into acids, such'as sulfuric acid,

being effected in a neutralizing vessel (neutralizer). Obviously the output of such neutralizer will be the greater, the more ammonia is combined with sulfuric acid per unit of time and space. This output is however limited by the -M-that the heat of dilution, which is liberated all-water and sulfuric acid being mixed, and vthe heat of reaction cause the solution to be heated tothe extent that the escaping vapors will carry any a certain proportion of uncombined ammonia. Therefore, in order to avoid losses inniu- -tmgen, 'these vaporsmust be subjected to a re treatment with acid in order. to bind the animals contained therein. f I

In order to avoid these dimcultiesatheacid used *rmnemmmuon hasbeen-diluted, but this in-';-

3 waives thedrawhack, that in order to recover the llid ammonium sulfate, considerable energy for * flewof water. i '7 7 I It has therefore already been suggestedin con- 88 nflation witl'rthe productionof ammonium-nitrate wuac fonthe dilution of the nitric'acid asolution ammonium nitrate saturated in the cold. It has'further beensuggested to avoid an overevaporating the great quanti-- (c1. ass-r19) monia gas are made to react with each other to form a solution of' sulfaterand'lor .bisulfate, whichonbeinjg cooled to about 20 .C. will not yet allow any crystals to separate out. The heat evolved in this reaction is removed by ,cooling'in a separate cooler and thecold solution is then introduced into the main neutralizer, in I which further quantities of are with sulfuric until solid ammonium sulfate separatesgout from the solution. r g I By causing .a consid rable 'partof the neutralization to take place in the preliminary stage and abstracting the heat deyelopedin the reaction by cooling, the evolution of heat of reaction in the main neutralizer will be muchllower. so in this manner the output of the neutralizer can be considerably increased without any ammonia being carried away by vapors escaping from the heatedsolutiong The sulfate thus formed be e rat vo in nvd s an a t r a We may also add to the mother liquor separated from the solid salt fresh .quantities,of ld, this mixture being then made to circulate through the system, being introducedeitherintorthe preliminary or themain neutralizer by a pump sr qu ed ine c indivi as We may produce a' solution of sulfa in th p liminary n utralizer wlay mm- ,ing "in, .a rapid cycle, whereby the dimensions of cthe ,prelinhnary neutralizer and .the cooler can be s ca l lre ucedcorrespondi ga P t acid then be continuously introduced into neutralizer. v a w welmamjals operajte in such'lmann'crthatpnly the heat of dilutionldev'eloped by addition of water to the acidds'removed ina separate yessel, the" dilute acid beingccibldbefofe introduc- 'heatk'flcf the solutim by cooling. However this} ,i-ng sam in m neu raliz s. I

of the ammonium salt will separate out on the outer wallsof the cooling pipes, which' are thus covered with a solid crust of the salt, and this crust will form a heat insulation, which. will reduce the cooling action to a minimum;

We have succeeded in considerably improving the output of the neutralizing step by causing the basic constituent and the acid, for instance ammonia and sulfuric acid, to react with each other in 'two or more stages, the solution obtained inone stage being cooled before entering the next succeeding stage.

, In carryinc out our invention we may proceed for instance in such manner, that in a prelimi-,

nary neutralizing vessel sulfuric acid and am- .lamsienjnvnlves thedisadvantage that some; :Iruthe dra the A. .r ,smiflcauon nd L in rpart thereofrizwo iormsorj qtm m apparatus embodying'our-invgution arejllustngted diagrammatically by was of example in vertical section. I 7

Referring to the drawings and first to Fig. l, a and b are pipes for supplying ammonia, and acid, (forinstance sulfuric acid) respectively, to the preliminary neutralizer A. The quantities of ammonia and acid are so chosen, that in the preliminary neutralizer a solution is formed, which is not saturated ;at 20 c. The heat or reactionis abstracted in'the cooler B, through which the solution is made to flow before entering the main neutralizer G, into which further quantities of ammonia are introduced through no the conduit c. From the bottom tap D the solution formed in the main neutralizer fed into the centrifuge Z, where the solid salt-is separated froni the mother liquor. To this liquor we prefer adding part of the acid required in the main reaction, in order to heat the liquor, thus preventing the separation of salt therefrom. which might clogthe pipes. This addition of acid to the liquor takes place, in the vessel G through i e- 2; The mixture of motherliquor and acid is then returned by means of .a rotary Pump through pipe 0 into the preliminary neu-' tralizer or through pipe. 1: into the main neu-' tralizer C.

In the modification illustrated in Fig. 2, two separate circulation systems are provided and the size of the preliminary neutralizer and cooler can then be reduced. Thesolution of ammonia salt forming in the preliminary neutralizer A is kept in-rapid circulation between the preliminary neutralizer'A and the cooler 15' by means of a rotary pump M, which forces the cold solution back into the preliminary neutralizer A, only that quantity of. the solution being allowed to escape into the main neutralizer C, which corresponds tothe fquantity of'acid supplied into the main neutifalizer.

Thejdistribution of the solution formed in A is controlled by valves n and o inserted in the pipes 11 and s leading from the delivery pipe t of the pump M to the preliminary and main neutralizer, respectively.

The mother liquor from the main neutralizer C can be returned into this neutralizer asdescribed with reference to Fig. l;

By thus subdividing the reaction into two or more stages and providing for a cooling of the liquor between the single stages, the output of V the neutralizer is greatly increased;-

In the claims theterms neutralizing and neutralization are intended to include both "partial and total neutralization. v I Various changes may be made in the details *disclosed in the foregoing specification without departing from the invention advantages thereof.

In the claims afiixed to" this specification no j'seljection'ot any particular modification ot the" invention is intended to the exclusion of other modifications thereof 7 and the right to subsequently make claim' to"any'modification not covered by expressly reserved.

We claim: t; 1. In the process of producing an ammonium 7' by neutralizing an acid with ammoniain two k stages and cooling the liquorbetween the stages,

the step of producing in the first stage afsolution,

which is not saturated at about 20 C.

arter effecting neutralization.

2. The process of producing an ammonium salt I by neutralizing an acid with ammonia comprising first diluting the acid, cooling orf sacrificing the 7 inc there- 3. The process of producing an ammonium salt by neutralizing an acid with ammonia comprising first diluting the acid with mother liquor resulting from a preceding operation cooling the mixture and thereafterefiecting neutralization.

'4. In the'manufacture of ammonium salts by the saturation method, the process which comprises partially neutralizing an acid corresponding to such a salt with ammonia,'passi.ng the resulting reaction products through a cooling zone wherein the temperature is lowered substantially, adding additional ammonia in a further stage of the. process and recovering an ammonium salt from the resulting reaction products.

' 5. The process of claim 4 wherein the partially neutralized reaction products are cooled to a temperature just above the crystallization point.

6. The process of claim {wherein cooling of the.

partially neutralizedreaction products is accomplished by cycling a stream of said products through said cooling zone and back to the partial neutralizing stage of the process.

7. The process of claim 4' wherein the acid neutralized is sulfuric acid.

8. In the manufacture of ammonium salts by the saturation method,the process .which'comprises reacting ammonia with'an acid liquor in an initial ammoniating stage, positively cooling the ammoniated reaction products by passing the same through a cooler, further reacting the said products with ammonia in a second ammoniating stage andseparatelyrecovering an ammonium salt and a'mother liquor from the resulting ammoniated reaction products.

9. The process, of claim 8 wherein the mother liquor is recycled'to at least one stage of the process. 7 i

.10. The process of claim 8 wherein the mother liquor is recycled to the initial ammohiating stage 11 cycled to the second ammoniating stage of the process. c r

14. 'I'heprocess of claim 8 wherein acid is added to the mother liquor and the acidified liquor. is 1 then cycled to a preceding step of said process.

FRIEDRICH JOST.: I

GI'j'NTHER HORNUNG. 

